A symbol is defined in the following way:
We are very familiar with the use of symbols. A blinking red light means "stop." The dollar sign is symbolic of money. A dove is symbolic of peace; roses are symbolic of love. Black is symbolic of evil or death. In literature an author will often use a symbol to send the reader a message—one that often supports a theme (a "life truth" the author wishes to share with the reader) in the story.
Often the indication that something is being used as a symbol is its repeated use. It can be an animal or a color: but it is something that is generally associated with meaning that goes beyond the item itself.
There are several things that may be seen as symbols in Dumas' The Count of Monte Cristo. They include the ocean, the red purse, the two islands in the story, the potion or "elixir" that the count uses, Abbe Faria, and symbolic references to Christianity.
The ocean or the sea (water) is often symbolic of rebirth; a baptism is a form of rebirth. For instance, when Edmond is thrown into the sea, he is reborn: no longer Edmond Dantès, but soon to be the Count of Monte Cristo. His live has new meaning (though he is driven by rage and a need for revenge). It also is symbolic of the death of his life of imprisonment, isolation and helplessness at Chateau D'If and his new life of freedom, wealth and power.
The red silk purse is used first by old Morrel to try to save Edmond when he is first arrested. It is the same purse that Edmond uses to offer proof that Morrel's debts have been paid off.
"My father!" cried [Julie], out of breath, and half dead with joy -- "saved, you are saved!" And she threw herself into his arms, holding in her extended hand a red, netted silk purse...
Morrel took the purse...a vague remembrance reminded him that it once belonged to himself.
In the purse are all of Morrel's bills, paid, as well as a diamond for Julie's dowry. The purse is symbolic of the true affection and dedication of one friend for another.
Abbe Faria is symbolic of Edmond's struggle to find himself and his purpose. First, Faria teaches Edmond something he never intended:
"I regret having helped you in your investigation and said what I did to you," he remarked.
"Why is that?" Dantès asked.
"Because I have insinuated a feeling into your heart that was not previously there: the desire for revenge."
Abbe Faria teaches Edmond other things, and then tries to make him change his course.
Here is your final lesson—do not commit the crime for which you now serve the sentence. God said, Vengeance is mine.
Edmond says he doesn't believe in God, but Abbe Faria quickly notes:
It doesn't matter. He believes in you.
The elixir is symbolic of Edmond's belief that he can control the world: the elixir seems to give him power of life and death. He is able to make Valentine appear dead; he mistakenly thinks he can bring Edward back to life with it. Edmond will realize that the elixir gives him no real power at all.
Chateau D'If becomes symbolic of undeserved punishment and suffering—it is hell. Ironically, Edmond meets Abbe Faria there who will give Edmond a way to escape and the wealth to start over. The island of Monte Cristo (the mount of Christ) is symbolic of new beginnings. Edmond is resurrected as the Count of Monte Cristo.